The invention relates to a method of navigating through television programs. The invention also relates to a television receiver for carrying out such a method and to a television transmitter for transmitting signals which enable or help the television receiver to carry out the method.
Recently, the transmission of electronic program guides (EPGs) has become an important issue in the field of television. An EPG assists the public in making selections from the large amount of television programs that are nowadays being offered, in particular since digital television transmission is becoming a mature technology. An EPG allows the user to obtain a xe2x80x9cWhat""s On Nowxe2x80x9d or xe2x80x9cWhat""s On Nextxe2x80x9d overview, and easily select a program of interest. To this end, descriptors defining properties of the programs such as scheduled broadcast dates and times, types of programs (for example, movies, entertainment, news, sports, etc.), rating, etc. are accommodated in the EPG.
Conventional EPG systems convey the program information along with one, usually analog, television signal. Television receivers display the information in a textual form, either alone or as an overlay over the currently selected television program.
It is an object of the invention to provide a method of navigating through television programs which further enhances the convenience of using electronic program guides.
To this end, the invention provides a method of navigating through television programs, comprising the steps of displaying a plurality of television programs as a mosaic of sub-images on a display screen, receiving one or more descriptors defining respective properties of each television program, receiving a user command identifying a selected descriptor value, and perceptibly marking the sub-images corresponding to television programs which have the selected descriptor value.
A mosaic screen is an attractive and user-friendly interface for selecting a television program from a plurality of available programs. It is achieved by the invention that such a mosaic overview remains displayed when the viewer wants to know which television channel broadcasts a desired type of program, e.g. a movie. Not only do the non-marked sub-images remain on screen, they also stay at the same position in the mosaic independent of the number of television channels that currently broadcast a movie. Once the user has associated a channel with its position in the mosaic, he will appreciate that said association is not changed by the theme search. Moreover, a steady picture is obtained.
The marking of sub-images may take many forms. An asterix or other special symbol may be displayed near the sub-images, the relevant channel names may be highlighted, the border lines of the sub-images may change color, etc. It is also possible to modify the appearance of the sub-images representing programs that are not desired, i.e. the sub-images corresponding to television programs which do not have the selected descriptor value. In advantageous embodiments of the invention, the brightness, contrast, size, or refresh rate (up to freezing into a still picture) of said sub-images is reduced.
The mosaic screen may be composed locally by the receiver from the various receivable television channels. It may also be transmitted by a transmitter along with one or more television programs. Such a transmitter is disclosed in the Applicant""s International Patent Application WO-A-95/28794. In accordance with the invention, the same transmitter also transmits, for each television program, the descriptors of said television program along with the mosaic signal. The above-mentioned receiver features can then be realized in a cost-effective manner. Preferably, the television programs, the mosaic signal and the descriptors are digitally encoded and multiplexed in a single bitstream.